KR20130119389A - Plate heat exchanger - Google Patents

Abstract

PURPOSE: A plate heat exchanger is provided to minimize the flow of a thermal medium without the interaction through individual plates and increase thermal flow rates for a predetermined size of plate. CONSTITUTION: A plate heat exchanger has flow channels through which a first flow and a second flow pass in concurrent or countercurrent flow. The flow channels are formed for the first medium between individual plates (1) joined together to form a pair of plates in each case and for the second medium between the pairs of plates joined together to form a stack (S) of plates. The individual plates within an inlet region (E) include guide blades (2) which are formed with stamped embossments and protrude into the flow channel. The guide blades are formed in an arch-shaped manner with an inflow leg (21) to be parallel to the main flow direction and an outflow leg (22) aligned at a predetermined angle to the inflow leg.

Description

Plate Heat Exchanger {PLATE HEAT EXCHANGER}

The present invention includes a flow channel through which the first and second flows pass in either a concurrent or countercurrent flow, which flow channels form a pair of plates in any case for the first medium. Formed between a plurality of pairs of plates formed between individual plates bonded to each other and joined to each other to form a plate stack for the second medium, wherein the individual plates and the plurality of pairs of plates extend parallel to the main flow direction. Connected to each other at the directional edge and the support surface, each individual plate has a diagonally inclined direction with respect to the first medium and includes corresponding inlet and outlet cross sections in the longitudinal direction, and transversely adjacent inlet for the second medium. A cross section and an outlet cross section, the outlet cross section for the first medium in any case by half the height of the inlet and outlet cross sections for the second medium; Discrepant, the individual plates are directed to a plate heat exchanger with profiling that generates turbulence.

This type of plate heat exchanger is used on a large scale with several meters of plate dimensions. The field of application here is used in incinerators, power plants, chemical plants, refineries, etc., where the resulting combustion heat of the flue-gases is used to heat the second medium.

The plate heat exchanger which concerns on the type mentioned above is disclosed by patent document 1 in detail. Guide blades are provided here to improve the efficiency of the heat exchanger or otherwise reduce the dimensions of the desired individual plate, which distributes the medium flowing through the inlet cross section over the entire flow channel width of the flow channel. In order to avoid the dead zone of the inlet region, in particular the plate region, which is located symmetrically adjacent to the longitudinal center, the guide blades are equipped with elongated outlet legs which protrude beyond the longitudinal center of the individual plates. In addition, in order to equalize the flow in the flow channel, the guide blades are arranged closer to the inflow cross section at the longitudinal center of the individual plates rather than in the longitudinal edge direction of the individual plates. Turbulence profiling that covers the surface area of as large individual plates as possible serves the same purpose.

Although such a device has indeed proved itself, problems still remain due to the flow bypass that forms on the individual plates and allows the heating medium to flow without interaction along the profiling. This is especially true for the edge regions of individual plates. As a result, the heat flow rate of the plate heat exchanger is reduced and thus the heat exchanger needs a longer individual plate for the desired performance.

German Patent No. 41 42 177 C2

It is therefore an object of the present invention to provide a plate heat exchanger which is as small as possible without the interaction of the heat medium through the individual plates and thus increases the heat flow at a constant plate dimension.

As a technical solution to achieve this object, we propose a flat plate heat exchanger according to the preamble of the independent claim, wherein the turbulence profiling is formed perpendicular to the main flow direction from the contact surface to the contact surface over the entire bottom, The plates have an edge channel having a cross section that varies in size over the longitudinal direction of the edge channel.

By such profiling that extends to the side edges over the entire width of the individual plates, the flow pattern can be adjusted while avoiding bypass. Thus, unlike the prior art, it can be avoided that the medium flowing over the individual plates enters the channel without profiling and only contributes little to the heat exchange. Overall, in contrast to the prior art, profiling closer to the side edges improves heat flow in the heat exchanger.

By reducing the size of the barrier-free bypass, the edge channel according to the invention also improves the flow pattern, which in turn increases the heat flow of the heat exchanger. Edge channels are formed in the shape of a labyrinth, in the region of the contact surface where the heat medium will find a flow channel without barriers and thus no interaction, ie in the edge regions of the individual plates. Due to the change in the cross section of the edge channel in the longitudinal direction, the medium flowing through the channel cannot continue to flow in a straight, barrier-free manner, but is subject to a backup effect at the reduced section with reduced cross section. Thus, the flow of media flowing through the edge channels of the individual plates without interaction and the resulting loss of performance are greatly reduced. As a result, the performance is improved by 5% compared to the prior art. This performance improvement can also be used to reduce the desired plate length of the heat exchanger to achieve the same performance with shorter individual plates.

Particularly advantageously, the edge channel is formed in a substantially S shape, ie in a multiple S shape. As a result, zig-zag blocking projections are formed on both sides of each edge channel, and the projections increase the interaction of the heating medium due to the reduction and extension portions. The blocking protrusion may be formed on one side or both sides of each edge channel, that is, a corresponding stamped protrusion may be provided on one side or both sides of the channel.

Advantageously the cross section of the edge channel can vary by more than 50%. As a result, the cross section without barriers to the medium is reduced by more than half in the reduction. In addition, in combination with the S-shaped structure, locally displaced flow channels are formed, further increasing the interaction between the medium and the heat exchanger.

In combination with the structure of the turbulence profiling that extends into each edge region of each individual plate according to the invention, the edge channel according to the invention has a synergistic effect so that a free flow path to the medium is essentially avoided. Thus, the medium flowing into the plate heat exchanger cannot be diverted through a flow path without bypass interaction. Unlike the prior art, according to the structure of the present invention, neither the bottom portion near the edge region of each individual plate nor the edge channel formed in the edge region between two individual plates shows such a bypass. This is because it is formed into a maze and the turbulent profiling extends into the edge region of each individual plate. As a result, the performance can be improved without changing the plate size, or the plate size can be reduced even at the same performance. There is no example of such a structure in the prior art.

In the present invention, the inlet and outlet legs are arranged at an angle of 140 ° to 100 °, preferably 135 ° to 112 ° with respect to each other. The shorter the guide blade, the steeper the inlet and outlet legs that can be disposed relative to each other. By combination with an inlet leg aligned substantially parallel to the main flow direction, an angle of 90 ° or less is possible without the risk that foreign matter accumulates on the guide blades and the inlet cross section is blocked.

And a guide blade formed by a stamped lump with individual plates in the inlet area protruding into the flow channel, wherein the guide blade is aligned with the inlet leg substantially parallel to the main flow direction and the outlet leg is constant relative to the inlet leg. It is recommended that it is formed in an arc shape with alignment at an angle, and the turbulence profiling of the individual plates includes stamped lumps. By stamping the said or individual plates it can be produced in a very simple and inexpensive manner. In addition, a uniform hump surface is optimal for improving the performance of the heat exchanger. Turbulent flow improves heat transfer and thus efficiency.

In addition, some of the humps may be formed as spacers for adjacent individual plates. In this way even a small distance between adjacent individual plates can ensure a certain plate spacing over the entire channel length and channel width. Such spacers may also be formed in the region of the guide blades to keep the individual plates in the region of the inlet and outlet cross sections at a predetermined distance from each other. Of course, it is also possible for all of them to act as spacers.

Furthermore, the guide blades of the inlet section do not protrude beyond the longitudinal center of the individual plates, that is, the guide blades are formed only in the half of the plate corresponding to each inlet section, inlet and outlet legs having substantially the same length, It is proposed that the inlet legs of the guide blades are in any case arranged at the transverse edges of the individual plates extending substantially perpendicular to the main flow direction. The adhesion of dirt particles is minimized because of the guide blades that are shorter and closer to the edges steeper relative to the main flow direction. In this way, blockage of the inlet cross section is reliably prevented, otherwise expensive cleaning will be required.

It is also proposed that in the region of the inflow cross section the turbulent profiling ring projects up to the guide blade and in the region of the outflow cross section. Due to this concave structure of the plate half positioned next to the inflow section, negative pressure is generated compared to the gas pressure inside the inflow section where the profiling is formed so that the incoming flue gas is sucked into the area without profiling. Thus, an even distribution of the inlet medium over the entire width of the plate is achieved, which in turn has a positive effect on the performance of the plate heat exchanger.

In the worst case, the structure of the guide blade according to the present invention and the structure of the turbulence profiling according to the present invention are combined to create a synergistic action, allowing equalization of the medium flowing into the heating plate throughout the plate width. Minimize the risk of contamination causing blockage of the guide blades. Unlike the prior art according to the above-mentioned patent document 1, the present invention proposes to intentionally deviate from the previous structure and to reduce the size of the guide blade, in particular compared to each outflow leg. In addition, by intentional departure from the foregoing prior art, the number of guide blades is significantly reduced. As a result of these solutions, the deterioration of the concerned media equalization according to Patent Document 1 surprisingly did not occur and was compensated in combination with the structure of the turbulence generation profiling. As a result of the structure according to the invention, the efficiency is improved compared to the prior art in terms of the distribution of the medium and at the same time the guide blade related contact surface for dirt particles, foreign matters and the like is reduced. As a result, in contrast to the previously known plate heat exchanger, the plate heat exchanger according to the present invention is not easy to be contaminated or clogged, so that the operation stability can be improved or the maintenance interval can be extended. A particularly positive effect in this regard is that, in contrast to the prior art, the outflow leg of the guide blade according to the invention is much steeper and shorter.

Advantageously, the guide blades are fully penetrated and stamped so that there is no gap for adjacent individual plates. Through this structure, the guide blades function sufficiently as a support or a spacer so that vibrations in the plate pairs and in the plate stack are reduced, thus making the overall heat exchanger structure more stable. According to this structure, a fully penetrated and stamped guide blade can be supported on the guide blades of adjacent individual plates or on opposite walls of the flow channel.

Further features and advantages of the invention appear in the following description with reference to the drawings.
1 is a perspective view of a plate stack formed from a plurality of individual plates, with guide blades and profilings not shown for better representation as a whole.
2A is a plan view of an individual plate with guide blades and directed profiling.
FIG. 2B is a perspective view of a plate stack formed according to FIG. 2A from a plurality of individual plates. FIG.
3 is an enlarged detail view of an S-shaped edge channel.
Fig. 4A is a sectional view of the section " A " of the S-shaped edge channel.
Fig. 4B is a sectional view of the section " B " of the S-shaped edge channel.
Fig. 4C is a sectional view of the section " C " of the S-shaped edge channel.

An exemplary embodiment of a plate heat exchanger schematically shown in FIG. 1 shows in a perspective form a plate stack S of a plurality of individual plates 1 connected to one another to form a pair of plates P. FIG. Each individual plate 1 comprises a bottom 11 which lies on a side different from the longitudinal edge 12. Each of the individual flat plates 1 is provided with a contact surface 13 in parallel with these longitudinal edges 12, which are shifted in height relative to the longitudinal edge 12. The misalignment difference between the contact surface 13 and the corresponding longitudinal edge 12 is about twice the difference between the longitudinal edge 12 and the bottom 11. The bottom part 11 is thus situated in the middle of the height between the face of the longitudinal edge 12 and the face of the contact face 13. In this exemplary embodiment, the edges extending across the longitudinal edges 12 of the individual flat plates 1 lie approximately in the middle of the face of the longitudinal edge 12 or the face of the contact surface 13, respectively. In this way the transverse edges 14a, 14b are formed, which are of the same height as the surface on which the longitudinal edge 12 is placed and the surface on which the contact surface 13 is placed, ie on the surface of the bottom 11. Compared with the vertical direction. 1 clearly shows the transverse edges 14a and 14b facing each other diagonally.

In either case, the two of the individual flat plates 1 shown in FIG. 1 are connected in accordance with the illustration of the bottom of FIG. 1 to form a plurality of pairs of flat plates P. As shown in FIG. 1 shows by way of example a complete five pairs of flat plates P, wherein an additional individual flat plate 1 is arranged at the top of the top flat plate pair, which is also shown spaced apart from the top individual flat plate 1. Is connected to form a pair of flat plates.

When a plurality of pairs of flat plates P are connected in the region of the contact surface 13 to form the flat plate stack S, as a result, flow channels for two media involved in heat exchange are arranged at the top of each surface. In any case, one medium flows into the flow channel formed by the plurality of pairs of plates P, while the other medium flows into the flow channel formed by joining the plurality of pairs of plates P to each other to form the plate stack S. Flows into. The transverse edges 14a of the individual plates 1 lying here on the face of the longitudinal edges 12 are defined by the inlet cross section z1 or outlet cross section A1 of the flow channel for the medium flowing between the plurality of pairs of plates P. Form. The transverse edges 14b of the individual plates 1 extending from the face of the contact surface 13 are the individual plates 1 of each pair of plates P in the same direction as or opposite to the first medium. An inflow cross section z2 or an outflow cross section A2 is formed for the other medium flowing therebetween. 1 shows a counter-flow heat exchanger, with the inlet and outlet openings arranged diagonally so that the inlet sections z1 and z2 for one medium are next to the outlet sections A2 and A1 for the other medium, respectively. In other words, it is shown that in either case, the height of the pair of flat plates P is shifted by half.

2a shows an individual plate 1 according to the invention, the inflow cross section z1 extending from the longitudinal center to the longitudinal edge 12 over half of the width of the individual plate 1. The individual plates have an inlet region E whose length in the main flow direction characterizes the path required for the inflow medium to spread over the entire width of the individual plates 1. In the figure four guide blades 2 are arranged to the right of the longitudinal centers of the individual plates 10, each comprising one inlet leg 21 and one outlet leg 22. Inlet leg 21 ) And outlet legs 22 are approximately equal in length, and enclose an angle between them of approximately 140 ° to 100 °. None of the outlet legs 22 protrude beyond the longitudinal center of the individual plate 1. In either case, the inlet leg 21 is attached close to the transverse edge 14a. The individual plates 1 have turbulence generating profilings 31 and 32, which are the entirety of the individual plates up to the contact surface 13. The profilings 31, 32 consist of a plurality of humps 31, 32 stamped onto the individual plates 1, which are inlet section 21 up to the guide blade 2. Extends in the region of and becomes concave in the region to the left of the longitudinal center have.

In the drawing according to FIG. 2, an S-shaped edge channel 15 is formed in the region of the contact surface 13, which has a cross-section with a variable size in the longitudinal direction.

2b shows a perspective view of a plate stack S formed of a plurality of individual plates 1. The interaction of the individual plates 1 can be clearly seen in this figure.

3 shows this edge channel 15 in an enlarged plan view. 4A, 4B and 4C show cross-sectional views of the edge channel 15 in different sections A, B and C according to FIG. 3. The cross section through which the medium flows is maximum at position A, while the cross section at positions B and C is less than 50% of the maximum cross section in any case, while the cross section at positions B and C is It is narrowed at the different sides of the edge channel 15. Here, the narrowed reduction portion is caused by the stamping projection 33. Since the image plane according to FIG. 3 has a partial circle shape, the channel of the S-shaped course is obtained as a whole in the longitudinal direction.

The invention acts so that the heating medium, here combustion flue gas, which flows into the individual plate 1 through the inflow cross section z1 collides with the inflow leg 21 of the guide blade 2 immediately adjacent to the transverse edge 14a. From this the combustion flue gas is directed over the outlet leg 22 which is arranged at an angle of approximately 140 ° to 100 ° with respect to the inlet leg 21. The inlet region E in the region of the inflow cross section z1 has profilings 31, 32 disposed immediately after the guide blade 2, whereas it has a surface symmetrical shape on the left side of the longitudinal center. Due to the fact that there is no profiling (31, 32) in the region of the inlet plate (1) located symmetrically, a pressure distribution develops above the profiling (31, 32) in the inlet region (E), which pressure guide blade The inlet combustion flue gas is drawn from (2) into the region without profiling. In this way the fuel flue gas is distributed evenly over the entire width of the plate to provide a uniform heat flux over the entire inlet plate 1 of the heat exchanger. In particular, because of the structure of the short and steep guide blade 2, the adhesion of the dirt particles on the guide blade 2 is reduced, so that clogging of the inflow cross section z1 is prevented. As a result, a flat heat exchanger having a low maintenance cost is not formed as a whole.

According to a variant embodiment, the individual plate 1 may comprise, in addition to the means shown above, an edge channel 15 comprising projections 33 stamped to form a maze. The medium reaching the edge regions of the individual plates 1 here flows through the edge channels 15 to reach the reductions and extensions of each channel cross section, causing a backup effect to promote the interaction of the media with the individual plates 1. Let's do it. As shown in FIG. 3, the combustion flue gas enters into the S-shaped edge channel 15, where the entire channel cross section is available in section A (see FIG. 4A). In section B (see FIG. 4B), the flue-gas should flow through the first bend with the cross section reduced in half. In this process, the above-described backup effect occurs. On the downstream side of this bend, the cross section temporarily expands again and decreases to half of the cross section again in section C (see FIG. 4C). However, this time follows the S shape of the edge channel 15 in the region of the opposite channel side wall. Therefore, as a whole, according to the prior art, the loss of performance due to the bypass in the edge region of the individual plate 1 is considerably reduced by the high interaction of the heat medium and the individual plate 1, and eventually the performance of the heat exchanger is improved. . This effect can be enhanced in that the turbulence generation profilings 31, 32 are formed up to the contact surface 13 over the entire width of the individual plates 1. This makes it possible to easily bypass the bypass and thus improve the performance of the heat exchanger.

A: outlet area A1: outflow cross section
A2: outflow section E: inlet area
P: plate pair S: plate laminate
z1: Inflow cross section z2: Inflow cross section
1: individual plate 11: bottom
12 longitudinal edge 13 contact surface
14a: transverse edge 14b: transverse edge
15: edge channel 2: protrusion
21: inflow bridge 22: outflow bridge
31: individual lumps 32: individual lumps
33: stamping process

Claims (10)

A flow channel through which the first and second flows pass in either a concurrent flow or countercurrent flow, the flow channels forming a pair of plates P in any case for the first medium; It is formed between the individual plates (1) bonded to each other, and is formed between a plurality of pairs of plate (P) bonded to each other to form the first medium and the flat plate stack (S) for the second medium, 1) and the plurality of pairs of flat plates P are connected to each other at the longitudinal edges 12 and the support surface 13 extending parallel to the main flow direction, and each individual flat plate 1 is diagonal to the first medium. Inlet and outlet sections z1, z2, A1, A2 arranged in the longitudinal direction and corresponding in the longitudinal direction, and inlet and outlet sections z1, z2, A1, A2 that are transversely adjacent to the second medium; ) And inlet and outlet cross sections (z1, z2, A1, A2) is in any case shifted by half of the height of the inlet and outlet cross-sections z1, z2, A1, A2 for the second medium, and the individual plates 1 are provided with profiling 31, 32 for generating turbulence. In flat plate heat exchanger,
The profiling (31, 32) for generating the turbulence is formed perpendicular to the main flow direction up to the contact surface (13) over the entire bottom (11),
In the region of the contact surface, the individual plate (1) comprises an edge channel (15) having a variable cross section over the longitudinal direction of the flow channels. 2. The plate heat exchanger as claimed in claim 1, wherein the edge channel (15) is formed to be substantially S-shaped or multiple S-shaped. 2. The plate heat exchanger as claimed in claim 1, wherein the cross section of the edge channel (15) can vary by 50% or more. The method according to one of the preceding claims, wherein the individual plates (1) in the inlet region (E) comprise guide blades (2) formed by stamped protrusions extending into the flow channel, said guide blades (1). (2) is formed in an arch shape with the inlet leg 21 aligned substantially parallel to the main flow direction and the outlet leg 22 aligned at an angle with respect to the inlet leg 21, wherein the inlet leg ( 21) and said outlet leg (22) are arranged at an angle of 140 ° to 100 ° with respect to each other, preferably 135 ° to 112 °. 5. Flat plate heat exchanger as claimed in claim 1, characterized in that the profiling (31, 32) generating turbulent flow has stamped lumps (31, 32). 6. Plate heat exchanger according to claim 5, characterized in that part of the hump (31, 32) is formed as a spacer for adjacent individual plates (1). The guide blade (2) of the inflow section (z1, z2) does not protrude beyond the longitudinal center of the individual plate (1), the inflow leg (21) according to one of the claims 4-6. And the outflow leg 22 have substantially the same length, and the guide blade 2 is arranged at substantially the same distance from the corresponding transverse edges 14a and 14b of each individual plate 1. heat transmitter. 8. The turbulent profiling 31, 32 protrudes from the inlet region E of the inflow sections 21, 22 to the guide blade 2. A flat plate heat exchanger, characterized in that it is concave in the region of the outflow end surfaces A1 and A2 which are symmetrically adjacent to the longitudinal center of the individual flat plate 1. 9. Flat plate heat exchanger as claimed in claim 4, characterized in that the guide blade (2) is completely penetrated and stamped so that it rests against the adjacent individual plates (1) with no gaps at all. 10. Flat plate heat exchanger according to claim 9, characterized in that the guide blade (2) acts as a support spacer.

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